Pencil draw-in device for pencil sharpener



June 20, 1967 KOHEI OGAWA 3,326,190

PENCIL DRAW-IN DEVICE FOR PENCIL SHARPENER Filed March 7, 1966 FIG. 1

INVENTOR KOHEI OGAWA ATTORNEYS United States Patent 3,326,190 PENCIL DRAW-IN DEVICE FOR PENCIL SHARPENER Kohei Ogawa, Tokyo, Japan, assignor to Tombow Pencil Company, Ltd., Tokyo, Japan Filed Mar. 7, 1966, Ser. No. 532,272 4 Claims. (Cl. 120--96) This invention relates to a device for drawing a pencil into a pencil sharpener.

Generally, a device for drawing a pencil into a conventional pencil sharpener consists of a chuck means mounted on the front side of the sharpener housing. In sharpening a pencil, the chuck is first pulled out and fixed in place with a stop, and then the chuck is opened by closing finger levers thereby to insert the pencil into the sharpener through the chuck. When the pencil has been sharpened, it is pulled out of the sharpener by opening the finger levers of the chuck again. Thus, the conventional devices are not only troublesome to handle, but are necessarily complicated mechanisms which add to the total'manufacturing cost of the pencil sharpener.

In view of these disadvantages of the draw-in devices for pencil sharpeners heretofore in use, it is an object of the present invention to provide such a device which is very simple to handle and less costly to manufacture.

The pencil draw-in device according to the invention is suited for use with a pencil sharpener or the like of the type having a cutter blade holder rotated by a handle and having a cutter blade also revolved by engagement with an internal gearon the blade holder. The draw-in device has two parallel rollers which are revolved by being geared to the rotary shaft of the holder and the speed of rotation is reduced sufiiciently for pencil sharpening and drawing a pencil into the sharpener for the purpose of sharpening it.

According to the invention, the engagement between the rotary shaft and the two rollers for drawing in a pencil which are disposed in front of the shaft is by engagement between the rollers and a disc fixedly mounted on the front end of the rotary shaft and which is revolved by the rotation of the rotary shaft.

In order to reduce the speed and torque of the rotary shaft to a value most appropriate for pencil sharpening and to permit the rollers to draw a pencil into the sharpener, the disc is provided with a protrusion or a plurality of protrusions, and a gear engageable therewith is mounted on one of the rollers or such gears are mounted on both of the rollers, so that the rollers can intermittently revolve inwardly or in the charging direction depending on the direction of rotation of the rotary shaft thereby to attain the above purpose. Alternatively, mutual friction between the disc and one end of the rollers or between the roller shafts and the rollers loosely mounted on the shafts drives the rollers, and the resulting slippage is utilized to reduce the draw-in force thereby to attain the above purpose.

In either case, the rollers are journaled on four legs which are integral with an elastic base of rigid plastic material, and the elasticity of the legs causes the rollers to exercise a suitable gripping pressure when a pencil is introduced therebetween.

Some embodiments of the invention will be described hereinafter with reference to the accompanying drawings, in which:

FIG. 1 is a side view, with the central portion in vertical section, of a pencil sharpener incorporating a device in accordance with the invention;

FIGS. 2 and 3 are a front and a rear view, respectively, of the embodiment of FIG. 1;

FIG. 4 is a front view of another embodiment of the invention; and

FIGS. 5 and 6 are front views of other embodiments of the invention.

Referring specifically to FIGS. 1, 2, and 3, the pencil sharpener shown comprises a sharpener housing 1, a holder 2 for a cutter blade 3, a handle 4 for rotating the holder 2, a ring 5 having an internal gear for rotary engagement with the cutter blade 3, a rotary shaft 6 which forms the front portion of the holder, a highly elastic base 7 of rigid plastic having integral legs 8 extending forwardly from the edge portions close to the four corners thereof, said legs being narrow at least at the portions where they are connected with the base so that the legs are sufliciently elastic to be used apart vertically away from each other, a disc mounted on the front of the base and fixedly secured to the front end of the rotary shaft 6 of said holder, said disc having a projection 10 on the periphery of the front face thereof, a pair of parallel roller shafts journaled on said legs 8 in front of the disc 9, two toothed wheels 12, one fixedly mounted at one end of one of the shafts, and the other mounted at the opposite end of the other shaft, said wheels being engaged by said projection 10 on the disc, and rolls 13 of resilient material secured on the central portions of said shafts.

Alternatively, as shown in FIG. 4, one of the toothed wheels on the parallel roller shafts 11 can be omitted and the disc 9 can be provided with a plurality of projections 10 spaced at equal intervals around the periphery thereof.

With the construction as above described, if a pencil end is pushed between the pair of parallel rollers 13 and the handle 4 is rotated, the holder 2 and hence the disc 9 fixed to the tip of the rotary shaft 6 on the holder will rotate, and the projection 10 on the disc will engage with the two toothed wheels 12 secured to the roller shafts 11 to rotate the two rollers 13 inwardly or in the charging direction, thereby to draw the pencil into the sharpener. A similar operation is achieved by providing a plurality of projections 10 and omitting a toothed wheel from one of the rollers shafts. In either case, the rollers 13 are revolved intermittently in the charging direction with the rotation of the rotary shaft 6 of holder 2 and the speed of the rollers 13 is suitably reduced to an average speed that permits a pencil to be fed into the sharpener at an adequate rate for sharpening. Furthermore, the legs journaling the roller shafts 11 are sufficiently elastic to apply a suitable pressure to the pencil being urged into the sharpener.

The embodiment illustrated in FIG. 5 is the same insofar as it concerns the structure for mounting on the main body of the pencil sharpener, interlocking mechanism, means for mounting the rollers 13, and the means associated with the base, as the embodiment described above in connection with FIGS. l-4. However, it is provided with teeth 14 on the periphery of disc 9 instead of the projections 10, which teeth can engage the toothed wheels fixedly secured to the rotary shafts 11, and the elastic rolls 13 on the roller shafts 11 are not fixed to the shafts but are loosely mounted thereon.

With such a construction, suitable friction is produced between the rolls 13 and roller shafts 11 so that the rolls can be rotated inwardly or in the charging direction. The slippage which occurs can be taken advantage of in reducing the running speed of the rotary shaft 6 until the pencil can be forced in at a suitable rate for sharpening purposes.

Further, as shown in FIG. 6, the periphery of the disc 9 in the embodiment as described with reference to FIGS. 1-4 can be extended forwardly or can have a ring 15 of rubber or the like bonded thereto, and the rollers 13 can be. provided with enlarged portions 16 having an increased diameter instead of the toothed wheels in order to utilize the friction and slippage between the periphery of disc 9 and the ends of rollers 13. Thus the friction and slippage between the two are'regulated so that a suitable draw-in pressure can be applied to a pencil for sharpening.

The present invention is not in any way limited to the embodiments thereof as above described, but is directed to a structure whereby a pencil is drawn into a pencil sharpener at a suitable speed for sharpening by the rotation of rollers having roller shafts which are journaled on elastic legs provided in front of a disc in such a manner that they can rotate with the rotation of the disc which is fixed to and interlocked with the rotary shaft forming the front end of the cutter holder of the pencil sharpener. To attain the above purpose, the speed and torque of the rotary shaft of the holder are reduced and the rollers are intermittently revolved inwardly or in the charging direction by the engagement between the projection on the disc and the gears on the rollers with the rotation of the rotary shaft, or a suitable friction is produced between the disc and roller ends or between the rolls and roller shafts and the consequent slippage is utilized.

As described hereinbefore, the present invention eliminates the defects of the draw-in devices of conventional pencil sharpeners which are complicated in their construction and cumbersome to handle, and the invention provides a draw-in device which has sucha simplified and concise construction that it can be manufactured at low cost and can be handled with amazing simplicity.

What is claimed is:

i 1. A device for drawing a pencil into a pencil sharpener which has a cutter blade holder having a shaft on the front end thereof and a handle on the other end of the shaft for rotating the cutter blade holder, said device consisting essentially of a disc fixedly secured to the rotary shaft on the front end of said holder, a single pair of parallel rollers in front of said disc and resiliently restrained against movement away from each other, and intermittent drive means connected between at least one of said rollers and said disc for transmitting the torque of the rotary shaft to the roller only intermittently and at a reduced speed for drawing the pencil into the sharpener at a reduced speed and at a torque which is most suitable for the purpose of pencil sharpening.

2. A device as claimed in claim 1 in which said intermittent drive means comprise intermittent gear means on said roller and said disc.

3. A device as claimed in claim 1 in which said rollers each comprise a hollow cylindrical roll, and said intermittent drive means comprise parallel shafts on which said rolls are loosely mounted, a gear on at least one of said shafts, and gear teeth on said disc engaged vwith said gear and driving said shaft, and slippage occuring between said roll and said shaft when a pencil is being drawn into said pencil sharpener.

4. A device as claimed in claim 1 in which said intermittent drive means comprises an enlarged portion on at least one of said rollers and a forwardly projecting portion on said disc around the periphery thereof engaging the enlarged portion of said roller, and slippage occuring between said roller and said forwardly projecting portion when a pencil is being drawn into said pencil sharpener.

References Cited UNITED STATES PATENTS 291,597 1/1884 Hoffman 120-96 2,664,071 12/1953 Guhl 120-96 LAWRENCE CHARLES, Primary Examiner. 

1. A DEVICE FOR DRAWING A PENCIL INTO A PENCIL SHARPENER WHICH HAS A CUTTER BLADE HOLDER HAVING A SHAFT ON THE FRONT END THEREOF AND A HANDLE ON THE OTHER END OF THE SHAFT FOR ROTATING THE CUTTER BLADE HOLDER, SAID DEVICE CONSISTING ESSENTIALLY OF A DISC FIXEDLY SECURED TO THE ROTARY SHAFT ON THE FRONT END OF SAID HOLDER, A SINGLE PAIR OF PARALLEL ROLLERS IN FRONT OF SAID DISC AND RESILIENTLY RESTRAINED AGAINST MOVEMENT AWAY FROM EACH OTHER, AND 